Bass-bar and coordinate bridge for violin family



Feb. 10, 1970 M. KASHA 3,494, 9

BA5S-BAR AND COORDINATE BRIDGE FOR VIOLIN FAMILY Filed Nov. 2'1, 196'?Fig 3 7 Top Plate Fig.2 6 D E /2/ 50 52 Fig. 7 3a 42 44 S 43 "x7 I] i! I7 I; 54 a W Ne -k 50d 7bi/piece End lrmm A I 34 28 30 ,4 I

.26 32 Michaef Kasfia l N VE N TO K United States Patent 3,494,239BASS-BAR AND COORDHNATE BRIDGE FOR VIOLIN FAMILY Michael Kasha,Tallahassee, Fla. (621 Escalona Drive, Santa Cruz, Calif. 95060) FiledNov. 27, 1967, Ser. No. 685,850 lint. Cl. 610d 1/02 US. Cl. 84-276 11Claims ABSTRACT OF THE DISCLOSURE The concept disclosed has to do withvibratory responsiveness, equable quality of tone and amplificationsusceptible of attainment in stringed instruments, for example, theviolin, viola, Violoncello and bass viol. Adequate sound level outputand compatible harmonic timbre and resonance depends on a number ofrelevant factors which involve the hollow body or sound chest and thecomponents which are carried by and are complemental thereto. To theends herein desired, the conventional sound chest, as such, remainsunaltered. On the other hand the usual bass-bar and regular symmetricalbridge are replaced by (I) an improved bass-bar and (2) a companionasymmetrical impedance matching bridge expressly designed and adapted tocounterbalance and coordinate with said bass-bar through the medium of(3) that portion of the top plate which is interposed therebetween. Thisresourceful united achievement produces greater amplitude and harmonicrichness of tone not now available in low cost and medium pricedinstruments.

This invention relates to stringed musical instruments such as, forexample, those of the violin family and pertains to the violin, viola,Violoncello, and bass viol and, more particularly, to a modifiedbass-bar and an asymmetrical companion bridge which, when in use,contributes its improved vibratory function to the bass-bar by way ofthe responsive top plate in a manner to amplify the sound output, toachieve balanced resonance, and a quality of tone which is pleasing andcomparable with that found only in precision made expensive instruments.

A conventional bass-bar, not shown, in a typical violin or the like hassignificant purposes and functions. One function is to amply support andcope with an appreciable force which is exerted downwardly on the bellyportion of the top plate by the usual string suspending bridge. A secondfunction is to distribute and communicate the localized vibrationsimparted to the top plate by the bridge, that is, from the locale of thebridge, to the orientated forward and rearward areas in a manner toeffectually drive the lowest frequency vibratory regions of the topplate. Craftsmen, acousticians and others conversant with violin makingand the many real and theoretical difficulties, repeatedly encountered,have no doubt recognized that the regular or conventional bassbar is ofgreatest cross-sectional dimension and accordingly thickest directlyunder the left or bass foot of the bridge-precisely where unhamperedmaximal vibratory response is unquestionably most needed. It followsthat one objective in the instant achievement is to modify and sensitizethe bass-bar by cutting or otherwise recessing the median portion in amanner to provide an arched zone which, as experimental testing hasshown, serves to 3,494,239 Patented Feb. 10, 1970 cope with thisheretofore unsolved response problem and overcomes the dulling andstultifying effect on the tone of the two lowest strings, for example, Gand D on a violin.

In carrying out the underlying principles of the present invention, thecentrally arched bass-bar provides (a) greater capability of motion forthe top plate (b) permits the bass-bar to carry out its normal functionand, at the same time, extends vibrations via the top plate in animproved manner to the marginal areas of the plate, and (0) provides aunique arched support adequate for the load and tension imposed by thebridge. To the ends desired, the dimension and shape of the archedportion will vary in a manner to be hereinafter set forth.

It may be here noted that the improved recessed and arched bass-bar ishighly and acceptably effective in combination with the herein disclosedimpedance matching asymmetrical bridge. This new bridge is so designedand constructed that it coacts with the belly and uniquely archedbass-bar, and, in so doing, it compensates for the inherent loss ofstrength and mechanical weakening attributable to the notching andarching of the median portion of said bass-bar.

A conventional violin bridge is known to have a complex set ofproperties in its function of coupling and transmitting the stringmotion to the top plate. Aside from these complexities, personsconversant with the study of bridges hold that the bridge has primarilya rising and falling motion in driving the top plate and predominat ngover longitudinal rocking motion. The rising and falling motion of thebass foot of the bridge, as contrasted with that relative to the treblefoot of the bridge, is assumed to be of a very different amplitudebecause of the internal acoustical structure (bass-bar vs. soundpost) ofthe resonating chamber of the hollow body. In the conventional bridgethe two feet of the bridge are identical in shape and orientation.Consequently, they could be described as a compromise on the motion tobe coupled.

The improved impedance matching bridge has feet which are asymmetricrelative to each other, distinguishable -from the substantiallysymmetric feet of the conven tional bridge. The G and D strings canimpart a vertical vibratory motion directly to the soundboard, thefundamental low-frequency mode being enhanced by the significantlylengthened right angularly disposed bass foot of the bridge. Thetreble-strings can impart a high-frequency elastic oscillation to thebridge, which is matched to the soundboard high-frequency harmonics by anarrowed treble foot of the bridge.

The improved bass-bar (divided and arched) is similar to theconventional one in overall profile, with the salient difference thatnear the center of the underside a generally parabolic (or hyperbolic)arch is cut, directly under the bass foot of the bridge, in contrast tothe conventional bass-bar which is thickest in this region. The purposeof this dimensionally reduced arch is to allow a much greater amplitudefor the soundboards fundamental vibrations on the bass side.

Briefly stated, the overall concept has to do with a hollowneck-equipped violin or an equivalent hollow acoustical body which ischaracterized by the usual bouts and which, as usual, is providedinteriorly with a standard soundpost coordinated with the right handf-hold and a bass-bar coordinating with the left hand f-hole, and

wherein the bass-bar, although similar in profile to a conventional one,is improved and a specially designed asymmetrical companion bridge isprovided for compatible use in interdependent combination with saidimproved bassbar.

In carrying out the principles of this invention the bassbar isstationed and the upper lengthwise edge is glued or otherwise fixedinwardly of the left f-hole in its regular lengthwise position and isproportional in length with the length of the top plate of the body.Near the center of the underneath lengthwise edge a notch or recess iscut or otherwise formed to define a prescribed arch (parabolic orhyperbolic, as the case may be). This notched arch divides the leadingand trailing components of the bass-bar and is oriented with the usualcentral nicks of the adjacent (left) f-hole so that it will assume alocale directly under the specially designed left or bass foot of theimproved asymmetrical bridge. This thus arched bass-bar and complementalbridge acting in conjunction therewith, results in greater amplitude(magnitude) and more desirable vibratory efiiciency on the low frequencyor G and D string side.

The improved asymmetrical bridge and arched bassbar lend themselves toacceptable modes of manufacture of violins, violas, violoncellos, bassviols and other instruments of the violin and viol group. Their adoptionand endorsed use and unique acoustical results will doubtless lead toimproved instruments at lowered cost, keeping in mind the usualstringent demands for quality wood for top plates, special varnishes,and other relevant time and labor consuming matters.

More explicitly, novelty is predicated on the aforementioned interruptedor arched bass-bar and asymmetric companion bridge with impedancematching and their relationship to each other and the intervening topplate coacting, as they do, to increase the sound output level with anattending gain in resonance and balanced tone.

While stress is placed on the improvement the present invention gives tothe response and timbre of the fourth and third strings of the violinfamily (G and D of violin, C and G of viola, etc.), experience has shownthat, to a lesser degree, the brilliance of the second and first stringsis also increased by the application of this invention.

These together with other objects and advantages which will becomesubsequent apparent reside in the details of construction and operationas more fully hereinafter described and claimed, reference being had tothe accompanying drawings forming a part hereof, wherein like numeralsrefer to like parts throughout, and in which:

FIG. 1 is a view in top plan of a conventional violin embodying theimproved bass-bar and showing the improved companion bridge.

FIG. 2 is an enlarged fragmentary detail view taken approximately on theplane of the section line 2-2 of FIG. 1.

FIG. 3 is an enlarged fragmentary view with portions broken awayillustrating the improved bass-bar and taken approximately on the planeof the section line 3-3 of FIG. 1.

FIGS. 4, 5 and 6 are views similar to FIG. 3 and which are included hereto bring out the fact that nominal modifications in the arched portionof the bass-bar (with or without the embedded wire) may be resorted toin actual practice if desired.

And FIG. 7 is a top plan view of the improved bridge by itself.

By way of introduction to the description of the details it may bestated here that the viola, Violoncello and double-bass (bass viol)differ primarily in size and not in contoured shape. The laws affectingtheir individual construction, as distinguished from the violin arebasically and proportionately alike. The underlying principle of theinventive concept is illustrated here in the form of the violin shown inFIG. 1. As already stated, the hollow body of the violin shown in FIG. 1is characterized by an. upper or forward bout 10, a lower or rearwardbout 12 and a middle bout 14 sometimes referred to as the waist. To besure the hollow body includes a conventional back (not detailed) and atop plate which is generally denoted here at 16. The conventional neck(including the fingerboard and other parts)is denoted generally by thenumeral 18. The f-hole on one side of the belly 20 is denoted at 22 andthe companion f-hole on the other side is denoted at 24. No alterationsin this hollow body or tone chest per se are herein resorted to. It isreiterated therefore that the invention has to do with the improvedbass-bar 26 and the companion improved asymmetrical bridge 37. Thebridge is detailed in FIGS. 2 and 7 and the bass-bar 26 in FIGS. 3, 4, 5and 6. In this description FIG. 3 will be used as the basis fordiscussion of the bass-bar. In fact, the generic aspect of the inventionis shown in FIG. 3 and the slight modification are shown in FIGS. 4, 5and 6. To simplify the description, like reference numerals will beemployed on like component parts in these views (FIGS. 36).

The upper uninterrupted longitudinal edge of the bassbar as usual isglued along its entire length to the underneath of the top plate orbelly 16. It is similar in overall profile to a conventional bass-barbut is uniquely different in that it is provided intermediate itsforward and rearward ends with a recess 28. Stated otherwise, theunderneath side only of the median portion of the bassbar is recessed at28 to define a complemental arch 30. The arch spans the recess and isvariable at will by the craftsman in a manner to increase the audibleoutput and to enliven the response and intensity of the tone primarilyof the two low-frequency strings (G) and (D) as evident in FIG. 2 Thethus reduced arch divides the forward or neck end portion 32 (FIG. 3)from the rearward end portion 34. As a strengthening feature, when amaximum gain of sound output is required calling for deep arches asshown in FIG. 3 or FIG. 4, a light spring metal wire 36' (or narrowband) may be embedded on the underside of the bass-bar, following thenotch and arch profile. Such a spring wire adds to the elastic momentand at the same time restricts plastic flow of the spruce top andreduced bass-bar under bridge loading.

The exact delineation and length of the notch 28 (archway) and thevertically reduced arch 30 can be varied to control, that is, increasethe in toto output and augmented intensity of the tone. For example, thelong and deep hyperbolic arch (FIG. 3) is contemplated for use onlow-priced student instruments in that it yields a satisfactoryincreasein sound output with enhanced depth of tone. By way of comparablecontrast the shallow hyperbolic arch (FIG. 6) achieves nominal change inoutput yet has a mellowing influence and effect on the tone of a raw,often harsh, newly made instrument. The parabolic arches shown in FIGS.4 and 5 serve well on fine new instruments to increase intensity of toneand mag nitude. The pattern revealed in FIG. 4 (as well as FIG. 6) canbe and has been resorted to for use on fine old instruments tonoticeably increase resonance, especially of the low-frequency 3rd and4th (D and G) strings.

It is reiterated here that the optional reinforcing wire feature 36while shown only in FIG. 3 is susceptible of use in the variations inthe arched shapes shown in FIGS. 4, 5 and 6.

The bridge 37 is similar in general overall appearance to a conventionalbridge which, as is well known, is provided at the bottom with identicalfeet. In the unique adaptation herein shown it is provided at the bottomwith a left or bass foot 38 and at the right (FIG. 2) with a treble foot40. It will be further noted from FIG. 2 that the cross-sectionaldimension of the foot 38 corresponds with the cross-sectional dimensionof the bassbar 26. Also this foot is elongated in a direction at rightangles to the lengthwise dimension of the body of the bridge andprovides a forward end portion 42 (FIG. 7) which projects at rightangles to and beyond the front face of the bridge and a rearward tipportion 44 which projects at right angles beyond the rearward face ofthe bridge. With respect to the treble foot 40 it Will be noted that theprojecting portions while likewise at right angles to the front and rearfaces are comparatively or relatively short as denoted at 46 and 48respectively. The crosssectional thickness of the bridge is increased asgenerally denoted at 50 in FIG. 2 conformable with the foot 38. Thethinner and tapering portion 52 is conformable with the shorter treblefoot 40. The sole portions of both bar and to compensate for themechanical weakening of the bass-bar resulting from the aforementionednotch 28 and reduced arch 30.

With further reference to the theory of the bridge, it will be evidentthat the left or bass foot 38 and right or treble foot 40 arecooperatively oriented longitudinally and transversely and that the soleportion or area under each foot is predetermined for its assignedpurpose. This comparable and relative variation constitutes mechanicalimpedance matching. It follows that a relatively small area of the topplate is driven with the usual soundpost acting as a nodal point. On thebass side, the lengthwise extension of the left or bass foot achievesmore etficient driving of the entire top plate when based on the topplate directly over the notched arch of the bass-bar.

What is claimed as new is as follows:

1, A stringed musical instrument in the violin and viol groupcomprising, a hollow resonant body characterized by forward, rearwardand middle bouts and embodying a top plate, a conformable back, and ribsintervening and connecting the marginal edges of said top plate andback, said top plate having a predetermined convex bridge seating bellyportion equipped with opposed left and right f-holes, said forward boutbeing provided with a forwardly projecting conventional neck, anelongated one piece bass-bar having an uninterrupted upper longitudinaledge secured along its entire length to the underneath of said topplate, the median lower longitudinal edge of said bass-bar being archeddirectly beneath said bridge seating belly portion and being reduced invertical cross-sectional dimension, whereby to provide increased andgreater amplitude of motion to the bridge seating belly portion of saidtop plate while at the same time achieving the nor mal bass-barfunction.

2. The musical instrument defined in and according to claim 1, andwherein the arched portion is cut to define a relatively deep hyperbolicarch susceptible of yielding an appreciable increase in sound output andan attending enhanced depth of tone.

3. The musical instrument defined in and according to claim 1, andwherein said arched portion is inverted V-shaped in appearance anddefines a relatively shallow hyperbolic arched portion which yieldsminimal change in output but achieves a mellowing effect on the tone of,for example, a raw, harsh and newly made instrument.

4. The musical instrument defined in and according to claim 1, andwherein said arched portion is of a shape and dimension to define aparabolic arch which lends itself for use on fine old instruments toincrease resonance, more particularly, resonance generated by the usuallow frequency 3rd and 4th strings.

5. The musical instrument defined in and according to claim 1, andwherein the aforementioned reduced vertical cross-section is of apredetermined degree and is proportional to the complemental forward andrearward portions of the over-all bass-bar and wherein the underneathedge of the reduced portion has a longitudinally bowed reinforcing wireembedded therein.

6. The stringed musical instrument defined in and according to claim 1,and, in combination, a companion impedance matching asymmetrical bridgehaving bass and treble feet, said bass foot being elongated in adirection at right angles to the vertical front and rear faces of thebody of the bridge, having leading and trailing tip portions projectingforwardly and rearwardly of said front and rear faces, respectively, thelongitudinal disposition 6 of said bass foot being designed to coact inregistrable alignment with the arched portion of the bass-bar, wherebyto compensate for the reduced structurally weakened but highly sensitivearched portion.

7. The stringed musical instrument defined in and according to claim 6,and wherein said bass foot is of a length proportional with the lengthof the complemental arch and is of a cross-sectional dimensioncorresponding with the cross-sectional dimension of said arched portion.

8. The stringed musical instrument defined in and according to claim 6,and wherein said bass foot is of a length proportional with the lengthof the complemental feet are fittingly applied to the convex or bellyportion 54 in the manner shown. This improved bridge is designed toexpressly coact with the improved arched bassarch and is of across-sectional dimension corresponding with the width of said arch, andwherein the bottom plan dimension of said bass foot is greater that thebottom plan dimension of said treble foot, said treble foot beingparallel with, similar in cross-section to but slightly shorter thansaid basss foot, whereby a relatively small area of the underlying topplate is driven, with the soundpost acting as a nodal point, and theenlongate bass foot contributing to more efiicient driving magnitude ofthe coordinating low-frequency area of said top plate.

9. In a stringed musical instrument, a top plate having a forward endportion, a rearward end portion, and an intervening bridge seating bellyportion having regulation left and right f-holes formed therein, and, incombination, an elongated bass-bar having an uninterrupted lengthwiseedge abutting and afiixed lengthwise to the underneath side of said topplate inwardly of but adjacent to and substantially paralleling saidleft f-hole, the median portion of the bottom edge of said bass-barbeing arched directly beneath said bridge seating belly portion andbeing reduced in vertical cross-sectional dimension, said arched portionserving to divide the overall bass-bar into companion forward andrearward portions joined by said arched portion in a manner to provide(1) greater flexibility and amplitude of motion to the top plate (2)normal bass-bar function of transmitting and extending local vibrationsof the top plate to marginal portions and edges of said top plate whileproviding, at the same time, a vibration responsive support for thetension imparted when a bridge is positioned for use on the bridgeseating belly portion of said top plate directly above and in alignmentwith said arched portion.

10. The stringed musical instrument defined in and according to claim 9,and, in combination, a companion impedance matching asymmetrical bridgehaving 'bass and treble feet, said bass foot being elongated in adirection at right angles to the vertical front and rear faces of thebody of the bridge, having leading and trailing tip portions projectingforwardly and rearwardly of said front and rear faces, respectively, thelongitudinal disposition of said bass foot being designed to coact inregistrable alignment with the arched portion of the bass-bar and tocompensate for the reduced structurally weakened but highly sensitivearch.

11. A stringed musical instrument in the violin and viol groupcomprising, a hollow resonant body characterized by forward, rearwardand middle bouts and embodying a top plate, a conformable back, and ribsintervening and connecting the marginal edges of said top plate andback, said top plate having a predetermined convex bridge seating bellyportion equipped with opposed left and right f-holes, said forward boutbeing provided forwardly of said bout with a projecting conventionalneck, an elongated one piece bass-bar having an uninterrupted upperlongitudinal edge secured along its entire length to the underneath sideof said top plate, the median lower longitudinal edge of said bass-barbeing arched directly beneath said bridge seating belly portion andbeing reduced in vertical cross-sectional dimension in a 7 8 manner toprovide increased and greater amplitude of 353,277 11/1886 White 84276motion to the bridge seating belly portion of the top 436,963 9/1890White 84276 plate while at the same time achieving the normal bass-766,049 7/1904 Loppentien 84276 bar function, and a companion impedancematching asym- 1,042,287 10/ 1912 Shaw 84276 metrical bridge having abass foot at one end and a 1,438,386 12/1922 Lucas 84276 treble foot atthe other end, said bass foot being adapted to reside atop the bridgeseating belly portion in regis- FOREIGN PATENTS trable alignment withthe underlying arched portion of 313,168 11/1920 ythe bass-bar in amanner to compensate for the weakened RICHARD WILKINSON Primary Examinerbut responsively sensitive arched portion.

10 I. F. GONZALES, Asslstant Examiner References Cited Us cl X R UNITEDSTATES PATENTS 84 309 155,353 9/1874 White 84276 168,820 10/1875 White84276 15

